Abstract 18844: Diagnosis of Thin-capped Fibroatheromas in Intravascular Optical Coherence Tomography Images: Effects of Light Scattering

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Taylor Hoyt ◽  
Jennifer Phipps ◽  
Deborah Vela ◽  
Tianyi Wang ◽  
Maximillian Buja ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Light Scattering ◽  
Coronary Arteries ◽  
Foam Cell ◽  
Imaging Modality ◽  
Fibrous Tissue ◽  
Image Feature ◽  
Optical Coherence ◽  
Fibrous Cap ◽  
Intravascular Optical Coherence Tomography

Objectives: Intravascular optical coherence tomography (IVOCT) images are recorded by detecting light backscattered within coronary arteries. We hypothesize that non- thin-cap fibroatheroma (TCFA) etiologies may scatter light to create the false appearance of IVOCT TCFA. Background: Conflicting reports are recognized about the accuracy of IVOCT for TCFA detection. Methods: Ten human cadaver hearts were imaged with IVOCT (N=14 arteries). Coronary arteries were sectioned at 120 μm intervals. IVOCT and histologic TCFA were co-registered and compared. Results: Of 21 IVOCT TCFAs identified by two independent IVOCT core labs (fibrous cap <65 μm, lipid arc >90°), only 8 were true histologic TCFA. Foam cell infiltration was responsible for 62% of cases in which either thick-capped fibroatheromas (ThKFAs) appeared like TCFAs or arterial tissue appeared like TCFAs when no lipid core was present. Other false IVOCT TCFA etiologies included SMC-rich fibrous tissue (15%) and loose connective tissue (8%). If the lipid arc >90° criterion was disregarded, 45 IVOCT TCFAs were identified, and sensitivity of IVOCT TCFA detection increased from 53% to 88%; specificity remained high at 93%, and the presence of a new IVOCT image feature called “bright streaks” increased positive predictive value (PPV) to 53%. New mechanisms for light scattering are proposed to explain the low PPV of IVOCT to identify true TCFA (44%), and explain why other plaque components can masquerade as IVOCT TCFA. Conclusions: IVOCT can exhibit up to 88% sensitivity and 98% specificity to detect TCFA, but PPV is limited due to multiple etiologies that cause light scattering similar to true TCFA. Disregarding the lipid arc >90° IVOCT TCFA requirement, and the identification of a new feature, bright steaks, can enhance the ability of IVOCT to detect TCFA. Combining IVOCT with another imaging modality that more specifically recognizes lipid will be important for increasing PPV in the future.

Abstract 12063: High-risk Plaque Co-localizes With Low Endothelial Shear Stress and Expansive Remodeling in Human Coronary Arteries: A 3D Optical Coherence Tomography Study

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Yiannis S Chatzizisis ◽  
Konstantinos Toutouzas ◽  
Andreas A Giannopoulos ◽  
Maria Riga ◽  
Antonios P Antoniadis ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Shear Stress ◽  
High Risk ◽  
Coronary Arteries ◽  
Vascular Remodeling ◽  
Pool Size ◽  
Optical Coherence ◽  
Fibrous Cap ◽  
Endothelial Shear Stress

Background: High risk plaque accounts for the majority of acute coronary events. Low endothelial shear stress (ESS) is a key factor of the natural history of atherosclerosis. The role of ESS in high risk plaque formation is not well studied in man. Hypothesis: To explore the association of low ESS with high risk plaque and to identify the ESS milieu and vascular remodeling response in high risk vs. non high risk plaque. Methods: 35 coronary arteries from 30 patients were 3D reconstructed with fusion of coronary angiography and optical coherence tomography (Fig A-D) . ESS was calculated in the 3D reconstructed arteries using computational fluid dynamics (Fig E) and classified into low, moderate and high in 3 mm long segments. In each segment: i) fibroatheromas were classified into high risk and non high risk based on fibrous cap thickness and lipid pool size ii) vascular remodeling was classified into constrictive, compensatory and expansive. Results: Fibroatheromas in low ESS segments had significantly thinner fibrous cap compared to high ESS segments (89±84 vs.138±83 μm, p<0.05). Lipid pool size was comparable across all ESS categories. The majority of low ESS segments co-localized with high risk plaques (29 vs. 9%, p<0.05), whereas the majority of high ESS co-localized with non high risk plaques (24 vs. 9%, p<0.05, Fig F ). Compensatory and expansive remodeling was the predominant remodeling response in low ESS segments containing high risk plaques. In non-stenotic fibroatheromas (expansive or compensatory remodeling) low ESS was predominantly associated with high risk plaques (29 vs. 3%, p<0.05) whereas high ESS was associated with non high risk plaques (Fig F) . Conclusions: Novel combined anatomic and functional imaging with 3D OCT showed that low ESS and non-constrictive remodeling are associated with high risk plaque in man. Further studies are needed to assess the role of ESS and vascular remodeling in high risk plaque rupture and precipitation of clinical outcomes.

scholarly journals Automated Volumetric Intravascular Plaque Classification Using Optical Coherence Tomography

AI Magazine ◽  
2017 ◽  
Vol 38 (1) ◽  
pp. 61-72 ◽  
Author(s):  
Ronny Shalev ◽  
Daisuke Nakamura ◽  
Setsu Nishino ◽  
Andrew Rollins ◽  
Hiram Bezerra ◽  
...  
Keyword(s):  
At Risk ◽  
Optical Coherence Tomography ◽  
Human Error ◽  
3D Visualization ◽  
Optical Coherence ◽  
Fibrous Cap ◽  
Plaque Classification ◽  
Coronary Events ◽  
Intravascular Optical Coherence Tomography ◽  
Interactive 3D

An estimated 17.5 million people died from a cardiovascular disease in 2012, representing 31 percent of all global deaths. Most acute coronary events result from rupture of the protective fibrous cap overlying an atherosclerotic plaque. The task of early identification of plaque types that can potentially rupture is, therefore, of great importance. The state-of-the-art approach to imaging blood vessels is intravascular optical coherence tomography (IVOCT). However, currently, this is an offline approach where the images are first collected and then manually analyzed an image at a time to identify regions at risk of thrombosis. This process is extremely laborious, time consuming and prone to human error. We are building a system that, when complete, will provide interactive 3D visualization of a blood vessel as an IVOCT is in progress. The visualization will highlight different plaque types and enable quick identification of regions at risk for thrombosis. In this paper, we describe our approach, focusing on machine learning methods that are a key enabling technology. Our empirical results using real OCT data show that our approach can identify different plaque types efficiently with high accuracy across multiple patients.

scholarly journals Intravascular optical coherence tomography light scattering artifacts: merry-go-rounding, blooming, and ghost struts

2014 ◽  
Vol 19 (12) ◽  
pp. 126017 ◽  
Author(s):  
J. Jacob Mancuso ◽  
David L. Halaney ◽  
Sahar Elahi ◽  
Derek Ho ◽  
Tianyi Wang ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Light Scattering ◽  
Optical Coherence ◽  
Intravascular Optical Coherence Tomography

scholarly journals Decorrelation Time Analysis Using Dynamic Light Scattering with Optical Coherence Tomography in an in vivo Mouse Tumour Model

2021 ◽  
Author(s):  
Timothy Wan Hei Luk
Keyword(s):  
Optical Coherence Tomography ◽  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Near Infrared ◽  
Imaging Modality ◽  
Preclinical Study ◽  
Infrared Light ◽  
Target Tissue ◽  
Optical Coherence

Optical coherence tomography (OCT) is an imaging modality that uses near infrared light interferometry for non-invasive, near-histological resolution imaging at the micron level. Concepts from dynamic light scattering (DLS) can be adapted to OCT to detect and measure the motions in the target tissue. Tissue dynamics can be observed by measuring the speckle decorrelation time (DT) of the tissue. DT analysis was performed in a preclinical study to demonstrate the repeatability and feasibility of using DLS-OCT to observe mouse tumours undergoing cisplatin treatment over a 48-hour period. Differences in the average DT data were observed for control and cisplatin-injected mice. Image segmentation based on DT values was also performed to subtract the DT contributions of pixels at blood vessel locations, resulting in the improvement of average DT calculations of the tumour tissue. The results presented are a preliminary step to analyzing and monitoring tumour growth and treatment response in vivo.

scholarly journals Development Of Dynamic Light Scattering Optical Coherence Tomography Methods For Detecting Cell Death

2021 ◽  
Author(s):  
Nico Joseph John Arezza
Keyword(s):  
Cell Death ◽  
Optical Coherence Tomography ◽  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Exponential Decay ◽  
Morphological Changes ◽  
Imaging Modality ◽  
Optical Coherence ◽  
Cross Sectional ◽  
Single Exponential

Dynamic light scattering (DLS) techniques can provide information about the quantity, size, and motion of light scatterers within a volume based on temporal fluctuations in its light scattering profile. In DLS, autocorrelation functions (ACFs) are computed from light intensity vs time signals acquired from optical imaging setups. A parameter known as the decorrelation time is computed from each ACF and is inversely related to the average motion speed of scatterers within the imaging volume. Optical coherence tomography is an imaging modality that generates 2D cross-sectional images based on light backscattered from a sample, and the combination of DLS with OCT is known as dynamic light scattering optical coherence tomography (DLS-OCT). Previously, DLS-OCT has been used to detect apoptosis, a form of programmed cell death, in non-adherent leukemia cells. Cells undergoing apoptosis experience predictable morphological changes that results in an increase in intracellular motion, and therefore a decrease in decorrelation time. We applied DLS-OCT methods to quantify the decorrelation times in adherent breast cancer cell pellets that were either untreated, treated with 20 ng/mL paclitaxel for 24 or 48 hours, or deprived of media for 24 or 48 hours. The mean decorrelation times in the paclitaxel-treated and nutrient deprived groups were significantly lower than in the untreated cells (p<0.05), suggestive of increased intracellular motion due to morphological cellular changes associated with cell death. We also investigated a new model to fit to ACFs generated by DLS-OCT of cell pellets. Typically, ACFs are fit to single exponential decay curves. We developed a model that expresses the ACFs from in vitro experiments as a sum of multiple exponential decay curves using an algorithm known as CONTIN. The curves produced by CONTIN fitted the experimental data much better than the single exponential decay fits. We speculate that the CONTIN fits, each of which resembled a superposition of three exponential decay functions, may result from light scattered from three different types of scatterers within cells, such as lysosomes, mitochondria, and nuclei.

scholarly journals Decorrelation Time Analysis Using Dynamic Light Scattering with Optical Coherence Tomography in an in vivo Mouse Tumour Model

2021 ◽  
Author(s):  
Timothy Wan Hei Luk
Keyword(s):  
Optical Coherence Tomography ◽  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Near Infrared ◽  
Imaging Modality ◽  
Preclinical Study ◽  
Infrared Light ◽  
Target Tissue ◽  
Optical Coherence

Optical coherence tomography (OCT) is an imaging modality that uses near infrared light interferometry for non-invasive, near-histological resolution imaging at the micron level. Concepts from dynamic light scattering (DLS) can be adapted to OCT to detect and measure the motions in the target tissue. Tissue dynamics can be observed by measuring the speckle decorrelation time (DT) of the tissue. DT analysis was performed in a preclinical study to demonstrate the repeatability and feasibility of using DLS-OCT to observe mouse tumours undergoing cisplatin treatment over a 48-hour period. Differences in the average DT data were observed for control and cisplatin-injected mice. Image segmentation based on DT values was also performed to subtract the DT contributions of pixels at blood vessel locations, resulting in the improvement of average DT calculations of the tumour tissue. The results presented are a preliminary step to analyzing and monitoring tumour growth and treatment response in vivo.

scholarly journals Development Of Dynamic Light Scattering Optical Coherence Tomography Methods For Detecting Cell Death

2021 ◽  
Author(s):  
Nico Joseph John Arezza
Keyword(s):  
Cell Death ◽  
Optical Coherence Tomography ◽  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Exponential Decay ◽  
Morphological Changes ◽  
Imaging Modality ◽  
Optical Coherence ◽  
Cross Sectional ◽  
Single Exponential

Dynamic light scattering (DLS) techniques can provide information about the quantity, size, and motion of light scatterers within a volume based on temporal fluctuations in its light scattering profile. In DLS, autocorrelation functions (ACFs) are computed from light intensity vs time signals acquired from optical imaging setups. A parameter known as the decorrelation time is computed from each ACF and is inversely related to the average motion speed of scatterers within the imaging volume. Optical coherence tomography is an imaging modality that generates 2D cross-sectional images based on light backscattered from a sample, and the combination of DLS with OCT is known as dynamic light scattering optical coherence tomography (DLS-OCT). Previously, DLS-OCT has been used to detect apoptosis, a form of programmed cell death, in non-adherent leukemia cells. Cells undergoing apoptosis experience predictable morphological changes that results in an increase in intracellular motion, and therefore a decrease in decorrelation time. We applied DLS-OCT methods to quantify the decorrelation times in adherent breast cancer cell pellets that were either untreated, treated with 20 ng/mL paclitaxel for 24 or 48 hours, or deprived of media for 24 or 48 hours. The mean decorrelation times in the paclitaxel-treated and nutrient deprived groups were significantly lower than in the untreated cells (p<0.05), suggestive of increased intracellular motion due to morphological cellular changes associated with cell death. We also investigated a new model to fit to ACFs generated by DLS-OCT of cell pellets. Typically, ACFs are fit to single exponential decay curves. We developed a model that expresses the ACFs from in vitro experiments as a sum of multiple exponential decay curves using an algorithm known as CONTIN. The curves produced by CONTIN fitted the experimental data much better than the single exponential decay fits. We speculate that the CONTIN fits, each of which resembled a superposition of three exponential decay functions, may result from light scattered from three different types of scatterers within cells, such as lysosomes, mitochondria, and nuclei.

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